Miniature heads for dental angle handpieces



E. HOFFMEISTER ET AL MINIATURE HEADS Foia DENTAL ANGLE HANDPIECES Filed ma 17, 1955 FIG. 3 FIG.1

Sept 17, 1957 FIG. 4v

United States Patent MINIATURE HEADS FOR DENTAL ANGLE HANDPIECES Erich Hoiimeister and Kurt Rohm, Biberach-Riss, Germany Application May 17, 1955, Serial No. 509,079

4 Claims. (CI. 32-27) The invention relates to miniature heads for angle h andpieces for dental purposes.

The invention has for a main object to provide such a miniature head which has a narrower and shorter head body and contains a smaller top drive member and hearing than a normal size head, with a back cover plate serving as a closure for the rear face of the head body and which is pivotable relatively to the said head about a pivot member for freeing an opening in the rear head wall through which the usual top drive member and, if required, its bearing can be removed.

Whereas, in the case of normal heads, the pivot member for the coverplate is in the form of a stud screwed into a tapped hole in the rear wall of the head, since a normal head has sufficient wall thickness to take a hole of this kind, according to the invention it is proposed that the pivot member be constituted by a hollow boss projecting from the rear head wall, which latter is made thinner by an amount corresponding to the axial length of the boss, and a fixing screw for the cover plate is screwed into the hollow boss. With this pivotal arrangement, the reliable cover plate construction, which permits of the easy removal of the top drive and the associated bearing from the rear head opening, can also be used for miniature heads.

A further feature of the invention consists in a particularly simple construction and arrangement of securing element for the drill or other tool to be carried by the head. Whereas this part has hitherto had a complicated construction which has to be secured in position by a special pin system requiring accurate machining and fitting, according to the invention the securing element is formed of a metal strip adapted to be inserted in a corresponding recess of the cover plate, the strip having an upper hookshaped end to fix the tool in position. The lower end of the securing element is apertured to engage around the boss about which the cover plate is pivotable. A stop pin, which limits the turning movement of the cover plate and slides in a groove of the rear head wall can also be fixed in a simple manner on the securing element.

For a better understanding of the invention and to show how the same may be carried into efiect reference will now be made to the accompanying drawings in which:

Figure 1 is a side elevation of a miniature head with the cover plate and securing element shown in section.

Figure 2 is an end elevation of the head with the cover plate and securing element removed.

Figure 3 is a front elevation of the cover plate.

Figure 4 is a front elevation of the securing element for the drill.

Figure 5 is a side elevation according to Figure 4.

Referring now to the drawings, a miniature head body has a tubular projection 1, in the form of a boss having an internally screw-threaded aperture 2 situated on the rear face of the head body, i. e. the face of the body remote from that through which the working end of the tool projects. A cover plate 4 pivotally mounted upon the said boss 1 and held in position by a fixing screw 3 which is screwed into the correspondingly threaded boss.

The securing element 5 is, as aforesaid, fiormed from a metal strip inserted in the corresponding recess 6 in the cover plate 4, and the upper hook-shaped end 7 of the strip serves to fix the tool (not shown) in position. The lower end of the securing element 5 is apertured to engage around the boss 1 as shown. The stop pin 8, which limits the turning movement of the cover plate and slides in the groove 9 in the rear head wall, is also fixed on the securing element 5. The cover plate 4 and securing element 5 can thus be pivoted from the working position shown in Figure 1 to release an engaged tool or to permit withdrawal of the top drive member and its bearing through the rear head wall.

We claim:

1. For a dental angle handpiece, a miniature head comprising a hollow body for supporting a dental tool shank with the end thereof projecting through an opening in the rear body wall, tool driving means in said body including a top driving member and bearing withdraw able through said opening, a hollow boss projecting outwardly from said rear wall, a combined cover plate and tool securing element mounted on said boss to pivot between a position in which said opening is covered and said tool locked and positions in which the tool is released and the opening exposed to permit withdrawal of said top driving member and bearing and screw means engaging said boss to retain said cover plate and securing element in position, the, thickness of metal in said rear body wall necessary to accommodate said screw being reduced from a determinable normal thickness by an amount equal to the axial length of the boss thereby permitting a reduction in overall head size.

2. A miniature head according to claim 1, in which the tool securing element is mounted in a recess in the cover plate face which adjoins said rear body wall and consists of a metal strip having upper hook-shaped end adapted to engage a key-way in the tool shank.

3. A miniature head according to claim 2, in which said metal strip is apertured pivotally to engage said boss.

4. A miniature head according to claim 3, in which a stop pin is engaged in a groove in said rear head wall to limit angular displacement of said cover plate and element.

References Cited in the file of this patent UNITED STATES PATENTS 2,051,718 Kaltenbach Aug. 18, 1936 

